36 replies to this topic

[Karl Mitchell-Shead]

I started off a bit off a 'flash head' and still very much like to use it in the right environment (as Arthur full well knows when i asked him to come along to a firework meet). In the space of a month flash powder is the lesser priority and i am now fascinated with BP, its so much more interesting, variable, applicable, SAFER and satisfyingly rewarding than flash!

I love a good bang (dont get me wrong!) Working with BP is far more enjoyable, nothing like a thick BP putty that looks good enough to eat!

[CCH Concepts]

there is defiantly more skill and art involved with bp. what i have found with any salutes i make to trick isn't so much to do with with the explosive as much as getting the containment right. if i can get a nice hard, thick and most important even casing and when it breaks it breaks all over Rather than in one place this produces a very low report, which is what i like a boom rather than a crack.

now one thing i will say before anyone asks this never involves anything other than plastic shells and pasting or cardboard tubes and pasting.

that being said i am interested to see what result can be got from very fast BP has anyone managed to get comparable results?

[Creepin_pyro]

A string-bound maroon will indeed make a most satisfying report, with no flash needed.

You may want to invest in some 3-ply Italian flax twine - perfect for all your spiking needs!

Even with a hastily thrown-together wrap of kraft, a little spiking will go a long way.

With the right confinement straight meal will work fine. I believe the Germans like to use grained BP glazed with dark Aluminium to pack an extra punch. Their military battlefield simulators are absolutely amazing.

[CCH Concepts]

A string-bound maroon will indeed make a most satisfying report, with no flash needed.

You may want to invest in some 3-ply Italian flax twine - perfect for all your spiking needs!

Even with a hastily thrown-together wrap of kraft, a little spiking will go a long way.

With the right confinement straight meal will work fine. I believe the Germans like to use grained BP glazed with dark Aluminium to pack an extra punch. Their military battlefield simulators are absolutely amazing.

what grain size would be used i use about 2mm for lift would that be to big.

also the Al, do they just shake the BP in Al powder or do they wet the Bp slightly and shake it. what method do they use?

i have recently spiked a Ti salute with cotton string,the same string i use for my BM. this was saturated in PVA. this gave a very nice report. but they was FP based, i will try BP next.


one thing i would like to add, i know i am again talking about salutes, but this is just because this thread was started again. I'm more interested in getting things like hummers and more visual effect right than salutes. which I'm sure most will agree is a welcome step forward.

[RFD]

Personally i would avoid shaking anything,genuine German dark sticks to anything and everything so dampening bp would be totally unnecessary,if you must use bp with Gd i suggest diapering small amounts and be aware of any static build up,even though bp is one of the more stable things we use, once mixed with very fine ali it becomes a lot more sensitive and powerful.

[CCH Concepts]

i had a feeling that might be the case, thats why i asked. percentage wise how much would need to be added to give a good coating.

also will a coating make it take fire easier or harder. i was thinking harder?

[RFD]

On the odd occasion ive used bp/gd,i diapered it at the same ratio as perc/ali flash=70/30 and depending on your bp grain size it will coat no problem,as for being harder to light, well larger mesh ali can be hard to light but 2 micron gd is very reactive otherwise it wouldnt be used for flash and to increase the potential of a prime to light,take care with this mix it sounds simple enough but its basicaly a form of flash and needs treating with respect.

[CCH Concepts]

hadnt throught of it like that. so is this almost like KNO3/Al flash then?

[starseeker]

You may want to invest in some 3-ply Italian flax twine - perfect for all your spiking needs!


I would be interested in getting some of this twine,any pointers where from?

[CanadianPyro]

Salutes tend to be the favored devices of the mad bombers and morons, simply out for the noise and destruction. They are simply interested in big booms without any respect for the art or knowledge of the hobby.

While this is true in many cases, some individuals are actually interested in the science of explosions. When you look beyond the basics of the hobby of pyrotechnics, there are entire knowledge bases that can be applied to each individual effect. I make lots of salutes; not because I'm a moron or a mad bomber, but because I am interested in the physics of sound and pressure, reaction mechanisms that effect the burn rate of compositions, the effects of casing geometry on internal salute pressure, etc. Being able to utilize this knowledge and produce a louder or more brisant salute is quite satisfying. I also enjoy many other aspects of the hobby, but I feel that it's unfair to label everyone who enjoys salutes as a mad bomber and/or moron.

As for the original post, a rocket launch is unlikely to set off even sensitive Chlorate compositions. Still, I would seriously advise against using Chlorates in flash, especially when you have an equivalent Perchlorate salt available.

Edited by CanadianPyro, 17 November 2009 - 09:41 AM.

[CCH Concepts]

While this is true in many cases, some individuals are actually interested in the science of explosions. When you look beyond the basics of the hobby of pyrotechnics, there are entire knowledge bases that can be applied to each individual effect. I make lots of salutes; not because I'm a moron or a mad bomber, but because I am interested in the physics of sound and pressure, reaction mechanisms that effect the burn rate of compositions, the effects of casing geometry on internal salute pressure, etc. Being able to utilize this knowledge and produce a louder or more brisant salute is quite satisfying. I also enjoy many other aspects of the hobby, but I feel that it's unfair to label everyone who enjoys salutes as a mad bomber and/or moron.

As for the original post, a rocket launch is unlikely to set off even sensitive Chlorate compositions. Still, I would seriously advise against using Chlorates in flash, especially when you have an equivalent Perchlorate salt available.

thanks for that comment, its good to hear that from someone more experienced than myself. thats where my mind set has been, but i didn't want to make that point because i felt it could be arrogant to do so without the experience to back it up.

the reason i originally asked is because there are dozens of chlorate report comps on thegreenmans site and having tried one some time ago it gave a very deep report, compared to the KCLO4/Al in the same tube making more of a crack. although alot of these call for mixing sulfur and chlorate which of course is a no no.

name Flash Thunder #2
Potassium chlorate 43
Antimony trisulfide 26
Aluminum, dark pyro 31

thegreenman

Edited by CCH Concepts, 17 November 2009 - 12:32 PM.

[CanadianPyro]

That composition likely produces a deeper report than standard 70/30 KClO4/Al flash because it is significantly overfueled. This will slow the reaction, and result in the production of a much slower moving pressure wave, which of course is perceived as a deeper boom. You could obtain the same effect by slowing KClO4 flash, though I find that 70/30 has quite a deep sound as it is.

Adding Antimony Trisulfide to any composition is dangerous, and significantly increases the composition's sensitivity to electrostatic discharge. The crystals are conductive and shaped like very small, extremely thin needles, so only a very small amount of current is required to heat them to the ignition temperature of the comp. It's analogous to using 24 gauge wire on an arc welder.

You may also want to look into Nitrate flash, as such comps tend to burn more slowly and produce deeper bangs than the equivalent (Close to stoichiometric) Chlorate/Perchlorate versions.

[CCH Concepts]

that makes sense i had wondered why people choose to use nitrate flash. i had thought it had something to do with the burn speed, my thought was that if the pressure wave is moving slower then there more chance of a uniform break on the case rather than it breaching on a weak point.

[CanadianPyro]

my thought was that if the pressure wave is moving slower then there more chance of a uniform break on the case rather than it breaching on a weak point.

It's actually the opposite. If the pressure builds more slowly, the casing will tend to fail at its weakest point, and release all of the gas through that small opening. That's why relatively slow burning compositions like black powder can fire a shell into the air without blowing up the mortar.

With fast flash powder, the gas is generated so quickly that the inertia of the end plugs is sufficient to keep them in place while the internal salute pressure continues to rise well above the failure pressure of the plugs. Fast flash powder can be used in thick-tubed salutes with paper thin end plugs, and still produce a uniform burst of the tube, even if its failure pressure is many times higher than that of the end plugs.

[CCH Concepts]

i've always found that if i didnt have really strong end plugs they would just blow out. any tips?